This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We are investigating the details of cation binding to DNA quadruplexes and DNA-ligand complexes as determined by Circular dichroism, Nuclear Magnetic Resonance (NMR), as well as computational methods. The analysis of these structures requires use of Chimera, MidasPlus, and Sparky, (all developed within the RBVI) as well as other programs. Chimera is also used to help visualize results and to obtain views and structural comparisons.